title: Dynamic contrast-enhanced MRI for prediction of breast cancer response to neoadjuvant chemotherapy: initial results.
abstract: OBJECTIVE
  The aim of this study was to establish changes in contrast-enhanced MRI of breast cancer during neoadjuvant chemotherapy that are indicative of pathology outcome.
  
  
  METHODS
  In 54 patients with breast cancer, dynamic contrast-enhanced MRI was performed before chemotherapy and after two chemotherapy cycles. Imaging was correlated with final histopathology. Multivariate analysis with cross-validation was performed on MRI features describing kinetics and morphology of contrast uptake in the early and late phases of enhancement. Receiver operating characteristic (ROC) analysis was used to develop a guideline that switches patients at high risk for incomplete remission to a different chemotherapy regimen while maintaining first-line therapy in 95% of patients who are not at risk (i.e., high specificity).
  
  
  RESULTS
  Change in largest diameter of late enhancement during chemotherapy was the single most predictive MRI characteristic for tumor response in multivariate analysis (A(z) [area under the ROC curve] = 0.73, p < 0.00001). Insufficient (< 25%) decrease in largest diameter of late enhancement during chemotherapy was most indicative of residual tumor at final pathology. Using this criterion, the fraction of unfavorable responders indicated by MRI was 41% (22/54). Approximately half (44%, 14/32) of the patients who showed favorable response at MRI achieved complete remission at pathology. Conversely, 95% (21/22) of patients who showed unfavorable response at MRI had residual tumor at pathology.
  
  
  CONCLUSIONS
  Reduction of less than 25% in largest diameter of late enhancement during neoadjuvant chemotherapy shows the potential to predict residual tumor after therapy with high specificity.
authors.affiliation: Department of Radiology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands. c.loo@nki.nl
authors.forename: Claudette E
authors.initials: CE
authors.lastname: Loo
authors.forename: H Jelle
authors.initials: HJ
authors.lastname: Teertstra
authors.forename: Sjoerd
authors.initials: S
authors.lastname: Rodenhuis
authors.forename: Marc J
authors.initials: MJ
authors.lastname: van de Vijver
authors.forename: Juliane
authors.initials: J
authors.lastname: Hannemann
authors.forename: Saar H
authors.initials: SH
authors.lastname: Muller
authors.forename: Marie-Jeanne Vrancken
authors.initials: MJ
authors.lastname: Peeters
authors.forename: Kenneth G A
authors.initials: KG
authors.lastname: Gilhuijs
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000628:therapy*; D017024:Chemotherapy, Adjuvant / Q000379:methods; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006571:Heterocyclic Compounds; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods; D009942:Organometallic Compounds; D010865:Pilot Projects; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C062402:gadoteridol; D005682:Gadolinium